Devices for transmitting torque from a drive and an output are commonly also designated as couplings. Couplings have been developed and marketed by the applicant for decades.
A differentiation is made between torsionally soft couplings and torsionally rigid (or torsion-rigid) couplings.
A coupling is designated as a torsionally soft (or elastic) coupling that as a result of a certain torsion permits a torsion angle between the first connection and the second connection in a range of typically for instance between 6° and 12° in the operating range that is to be expected, i.e. within the torques that are to be expected in a normal operation of the coupling. A torsionally soft coupling (also: so-called elastic coupling) has a resonance frequency that is selected so that it lies below the operating range (of the frequencies that are to be expected). Torsionally soft couplings in particular damp torque peaks at a particular frequency or in a particular frequency range, and protect for example the components (e.g. a gearing) arranged downstream of a drive (e.g. a diesel engine) from torsion non-uniformities.
Torsionally rigid couplings, by comparison, are couplings of an entirely different type. In a torsionally rigid coupling, a torsion angle between the first connection and the second connection is to be kept very small in the operating range of the coupling.
A torsionally rigid coupling is therefore an almost torsionally stiff coupling. Here, the resonance frequency is selected above, typically far above, the operating range of the coupling. Torsionally rigid couplings come into use in particular in cases of application where a torsion angle between the first connection and the second connection is not to be permitted, or is not necessary, in the typical operating range.
The invention relates to such rotationally rigid couplings of the last described type.
Within the scope of the present patent application, such couplings are regarded as torsionally rigid couplings that still permit a certain torsion angle between the first connection and the second connection of for example up to 0.5°, if applicable also up to 1.5°, in the typical operating range of the coupling, but prevent greater torsion angles.
Torsionally rigid couplings of the generic type are marketed by the applicant for example under the article designation CENTAFLEX-KE. Here, a flange element of a high-strength, glass-fibre-reinforced plastic is provided, which has an axially insertable hub radially on the inner side. The flange, in the shape of an annular disk, consists of plastic and is provided with reinforcing struts.
Radially externally on the ring flange, rubber bushes are provided, which permit a screw fastening of the coupling for example on the flywheel of a motor.
Owing to the rubber bushes, a radial offset in a very small extent up to 0.3 mm is able to be compensated.
A further torsionally rigid coupling of the generic type is marketed by the applicant under the designation CENTAFLEX-K. Here, a membrane-like, thin ring flange is provided, which likewise consists of a glass-fibre-reinforced plastic. In the region of the hub, an axial plug connection with a shaft is possible. The metal hub can be inserted with its radially outwardly projecting teeth into corresponding recesses of the coupling hub.